Like cbley, I'm not exactly sure what you mean either, but you could mean embedding a file in your assembly?
- Go into Visual Studio, click "add existing item" and choose your file.
- Change the Build Action on the file to "Embedded Resource"
When you run your application, you can extract the file binary to the file system like this.
//make sure MyNameSpace.MyFile.xls is the fully qualified name in your assembly to the file
using (Stream stream = Assembly.GetManifestResourceStream("MyNameSpace.Myfile.xls"))
{
byte[] buf = new byte[stream.Length];
stream.Read(buf, 0, stream.Length);
File.WriteAllBytes(@"C:\MyFile.xls", buf);
}